Archived

This topic is now archived and is closed to further replies.

Dragonmount

Do real aircraft have a Nav/GPS button as part of the autopilot?

Recommended Posts

That's my question. I realize that heavy aircraft have LNAV and VNAV, and various variants of the same, and I was wondering if real GA aircraft have this kind of feature if they have GPS equipped on the aircraft?

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

It all depends on the avionics equipment.. as to how it is implemented.

 

Garmins (GNS or G1000) have CDI buttons that select the navigation source:

 

NAV1, NAV2 on the G1000, GPS.

Share this post


Link to post
Share on other sites

Not as part of the AP, but as a data source for the HSI/NAV indicator. Such functionality is required for a certified GPS installation. Note that the GNS series of GPS has this switch on the front panel of the device.

 

If you wanted the AP to navigate from either a VLOC or GPS source then you would switch as decribed above, then usually select "NAV" on the AP. So, similar to what you see in FSX.

 

Is this what you were asking?

 

Bruce.

Share this post


Link to post
Share on other sites

I sometimes wonder about these differences too. I wonder if I got into a relatively simple plane say Cessna C-172 - in real life, would it be almost the same or does the limitations of the desktop environment mean there are a lot of significant differences between a VC and a real cockpit. 

Share this post


Link to post
Share on other sites

Not as part of the AP, but as a data source for the HSI/NAV indicator. Such functionality is required for a certified GPS installation. Note that the GNS series of GPS has this switch on the front panel of the device.

 

If you wanted the AP to navigate from either a VLOC or GPS source then you would switch as decribed above, then usually select "NAV" on the AP. So, similar to what you see in FSX.

 

Is this what you were asking?

 

Bruce.

 

yea, more or less, thanks. Since I cannot fly in real life, I want to do things as realistically as possible. Couldn't decide on my own if this was realistic or not, and I couldn't find anything on google about it.

Share this post


Link to post
Share on other sites

As far as the C172 is concerned, it should be possible with a good FSX product to get close to the real thing. But the big issue with any aircraft is the views of the outside world.... in real life your eyes are focused on 3D at infinity, in the sim they are focussed on 2D at 3 feet or so.... and despite the best intentions to create an illusion of reality, it's actually very different, especially when landing visually when a lot of visual perception is required...

 

Bruce.

Share this post


Link to post
Share on other sites

 

yea, more or less, thanks. Since I cannot fly in real life, I want to do things as realistically as possible. Couldn't decide on my own if this was realistic or not, and I couldn't find anything on google about it.

 

You know, even if you have a medical condition that makes it impossible to fly, you can take a ride with an instructor and have him/her show you the real deal- don't ever limit yourself.... :)

 

Bruce.

Share this post


Link to post
Share on other sites

You'd be surprised how many people find the vc helps them get used to the "feel" of a cockpit, the layout etc

Share this post


Link to post
Share on other sites

You'd be surprised how many people find the vc helps them get used to the "feel" of a cockpit, the layout etc

 

 

Yes- agreed- for instrument work it's a great trainer, and teaches one to know in which direction to look for instruments, etc.  This goes for both smaller GA planes, and the larger airliners that are often operated IFR regardless of weather.  I use it to "practice" cross country flights so I know what to expect when I get there, as far as airport layout and visual landmarks.

 

Bruce.

Share this post


Link to post
Share on other sites

... and despite the best intentions to create an illusion of reality, it's actually very different, especially when landing visually when a lot of visual perception is required...

Yes, and when I was doing flight training -- before it was discovered I had RP (retinitis pigmentosa) which gave me tunnel vision -- I found real world landings much easier than in FS because of that perception -- at least once I got into the habit of focussing on the end of the runway rather than the ground just below my nose. The latter habit is too easy to get into in FS and does you no favours.

 

Regards

Pete

Share this post


Link to post
Share on other sites

Very true gents.

 

I started my NPPL (M) some time back but my training is on hold (only 6 hours so far), and like Pete said, real world landings seem much more natural and intuitive than in the sim, because of the 1000s of cues and motion signals that your eyes are feeding your brain.    

 

In a real plane there is no real perception of 'left a bit' , 'right a bit' with regards to the flight controls, it's just done more intuitively and naturally.  (Similar to driving a car)....The sim feels very two dimensional and 'static' in this sense.

 

To the OP:   As Bruce and others said, most avionics fits will place the GPS/VLOC control (which is the same as GPS/NAV in the sim) within the GPS unit itself.  The button is often labelled "CDI" (Course Deviation Indicator).

 

However, some more retro-fitted units do indeed have a "GPS/NAV" switch more like the one in the sim.   I flew in a Robin DR400 once that had a non-Garmin (older) GPS ..... can't remember the make... that had a "GPS/NAV" switch exactly like that is FS.

Share this post


Link to post
Share on other sites

The C172R for example has the GPS/NAV switch as a factory standard, just like the default FSX model. It simply changes the source which drives CDI and autopilot. I think most aircraft with panel mounted GPS'es have such switches, it's not rocket science. 

 

The real C172R has also a second switch, GPS APR that allows GPS to drive GSI during approaches without ILS. 

 

Full VNAV is rare, and not used very often in GA world. 

Share this post


Link to post
Share on other sites

 

 


Full VNAV is rare, and not used very often in GA world.

 

Heck, in my real world flying days, having an autopilot at all in light GA was pretty rare...especially an A/P with any vertical modes. Of course, it's also been my experience that trimming a real aircraft for straight and level is much easier in the real world than in the simulator... again a lot more cues. In FSX, trim effectiveness is dependent on the quality of the aircraft's flight modeling... some trim up nicely, the majority are unrealistically "touchy". It's one of the first things I look at when evaluating the quality of an .air file.

Share this post


Link to post
Share on other sites

I just wish that Flight sim (Sublogic of course) had been around before I did my PPL, I'm sure it would have saved me heaps of money and time.

Share this post


Link to post
Share on other sites